Thermic siphon



Jan. 19 G. J. CHRISTENSON THERMIC S IPHON Filed Sept. 29, 1958 2 Sheets-Sheet l Jan. 7, 1941.

G. J. CH RISTENSON THERMIC SIPHONV Filed Sept. 29, 1938 2 Sheets-Sheet 2 Patented Jan. 7, 1941 UNITED STATES PATENT OFFICE 2,227,745 THERMIC sIPnoN Application September 29, 1938, Serial No. 232,349

9 Claims.

This invention relates to improvements in thermic siphons and it cohsi'sts of 'the matters hereinafter described and more particularly pointed out in the appended claims.

Thepr'e'sent invention is more particularly concerned with a duplex th'err'nie siphon especially adapted for use in the firebox of a locomotive boiler for increasing the superficial area of the firebox and the water steaming and circulating efiieiency of the boiler as a whole.

A siphon of this type includes a fiat hollow body formed to provide end and intermediate chambers having a common outlet opening through the crown sheet and inlet necks, each connected at one end to an end chamber of the body and each connected at the other end to a firebox sheet at a poiht below the crown sheet.

One of the objects of the present invention is to provide a siphon of this kind which provides better circulation or water in fireboxes to the end that the general eflicienoy of the boiler shall be increased.

Again, one of the objects of the present invention is to provide a siphon of this kind which 25 provides better circulation of water through the back water leg and through the rear ends of the side water legs.

Another object of the invention is to provide a siphon of this kind wherein it is possible to rovide a greater length in the inlet necks thereof and whereby greater flexibility is afforded for said necks to accommodate sheet movement in the firebox without cracking under temperature changes in said sheets.

A further object of the invention is to provide a siphon of this kind wherein the inlet necks extend in opposite directions from the body to cross each other, thereby making it possible to obtain a greater combined length of inlet and more adequate flexibility in the siphon as a whole.

In the drawings:

Fig. 1 is a longitudinal vertical sectional view through a combustion chamber type of locomotive boiler firebox embodying the preferred form of the invention.

Fig. 2 is a vertical sectional View through the same as taken on the line 2--2 of Fig. 1.

Fig. 3 is a longitudinal horizontal sectional view through the firebox as taken on the line 3'3 of Fig. 1.

Fig. 4 is a top plan view of a thermic siphon embodying one form of the invention, as it appears when removed from the firebox.

Fig. 5 is a fragmentary vertical detail sectional view through the rear end portion of a locomotive firebox having a siphon embodying a slightly modified form of the invention arranged therein.

Referring now in detail to that embodiment of the invention illustrated in the drawings, the 5 firebox shown therein ihcludes the crown sheet Ml that merges into the inner side sheets 'I I. The inner back sheet is indicated at l2, inner throat sheet "at l3, and the flue sheet is indicated at [4. Extending forwardly from said flue sheet are the 10 flues l5.

The outer rear sheet of the boiler is indicated at IB, and the outer side sheets and the outer throat sheet thereof are indicated at I l and I 8 respectively. Said sheets cooperate with the top 15 sheet IQ of the boiler in forming the back Water leg 20, front throat 2| and the side water legs 22 respectively, all in communication with the water space 23 of the boiler. The back and side water legs and the front throat are bottomed by a mud 20 ring 24 and portions of the inner and outer back sheets are formed to coast in providing a fuel door opening 25. The above mentioned construction is conventional in locomotive boiler fireboxes.

In the firebox is provided one or more of the improved siphons indicated as a whole as at 26. in I certain sizes of firebox where only one siphon is employed, it is disposed in the vertical medial line of the firebox. When two such siphons are employed as illustrated herein, they are disposed, one on each side of said line.

Each siphon as shown herein comprises a fiat hollow body formed to provide front and rear relatively deep compartments or chambers 21-28 respectively separated by an intermediate compartrne'nt 29 of less depth. The body includes spaced side walls 3030 suitably staybolted together and transversely rounded front and rear end walls 3| and 32 respectively. The side and end walls are flared outwardly around the entire top end of the body by means; of inside curved corners 33 to merge into a laterally extending flange 34. This flange is fitted to and welded in a suitable longitudinal opening in the crown sheet as indicated at 35. Thus the open top end of the siphon body provides a common discharge or outlet for all three compartments 21-28 and 29 respectively of the siphon body, into the water space 23 of the boiler above the crown sheet Ill.

The front wall 3i of the siphon body is disf posed at a relatively steep angle extending downwardly and rearwardly from the crown sheet to merge into a rounded corner 35. The rear wall of said body is also. disposed at a relatively steep angle extending downwardly and forwardly sublet neck 38.

stantially opposite that of the front Wall to merge into a rounded corner 31.

Associated with the rear compartment 28 of the siphon body is a downwardly and forwardly extending inlet neck 38. This neck which has a diameter greater than the width or thickness of the siphon body, is of substantial length and is arranged directly beneath and in the longitudinal plane of the body. The neck 38 may be made from a piece of seamless tubing and the front end of the neck is anchored in a flexible diaphragm 39 preferably flanged up from the top portion of the inner front throat sheet 13. Said neck has an angular inclination approximating that of certain conventional arch tubes 40 when such tubes are employed in the firebox, to coact with the necks 38 of both siphons in the firebox in the support of the bricks forming the fire arch as will appear later.

That part of the body providing the front end compartment is bent laterally as a whole to bring the rounded corner 36 to one side of the plane of the remainder of the body and the in- Associated with this laterally bent corner portion and operatively connected thereto is a second inlet neck 4|. Said neck which is also of substantial length, extends downwardlyand rearwardly from said corner portion 35 toward thelower rear end of the firebox to open through one of the sheets thereof. With such an arrangement, it is apparent that the inlet necks 38 and 4| which are located in different planes, laterally of the firebox, cross each other as best appears in Fig. 1. In Figs. 1 and 3, the inlet end of said neck 4| is shown as bent laterally to enter and be welded in a diaphragm 42 arranged in the side sheet ll near the inner back sheet l2. If desired, this end of said neck -may open through the inner back sheet as best 1 appears in Fig. 5. In either instance, the action is to provide a better circulation for the back water leg and for the rear end of the side water leg.

In the present instance, two siphons are arranged in the firebox. With such an arrangement, the inlet neck 4| for the front end com partment of the body of each siphon, is disposed outside of the plane of the inlet neck for the rear end compartment of the body and is located nearer the associated side sheet ll than the last mentioned inlet neck. When an arch is employed in the firebox, it is composed'of longitudinal rows of brick 43. The innermost rows of brick rest at their lateral margins upon the necks 38, and the arch tubes 40 respectively, while the outermost rows are supported upon said necks and upon the side sheets I !-II respectively.

The bottom of the intermediate compartment 29 is formed by the top portion of a substantially circular'formation 44, the ends of said circular formation merging into top sides of the respective inlet necks at this point. This circular formation approximately forms a laterally extending opening through the body of the siphon for the passage of the products 'of combustion and at the same time it permits a more flexible union between the siphon necks and the body at these points.

It is apparent that the necks which are relatively long are under compression when in a cold condition as when there is no fire in the firebox. Such compression, of course, is in relation to the body of the siphon and substantially equals the amount of movement due to expansion as when the firebox is being fired under service conditions. Under such conditions, when the siphon is under service heat and pressure only slight stresses, incapable of starting fracture at the circular formation and inside corners before mentioned, are present because the force of expansion will return the necks and associated siphon body parts to their normal positions and thus neutralize expansion. With the arrangement described, the long inlet necks provide flexibility so that siphon body movement with the crown sheet, under expansion and contraction due to temperature changes, is readily absorbed throughout the length of said neck. Thus the curvature induced in said neck in such movement is reduced in degree so that fractures are avoided.

'By the arrangement described, more heating surface is provided and this induces a greater water evaporating and steaming action, and a fore and aft circulation of water in the boiler, with a faster water movement through not only the back water leg but also through the rear end portions of the side water legs. Thus with the circulation described, the mud ring surface of the various legs is swept clean of sediment against accumulation.

It is pointed out that due to the rounded formation of the bottom portion of the front and rear end portions of the body, as well as the circular formation between said end portions, said parts of the body are swept clean by the circulating water and therefore sediment cannot accumulate at these points so that burning out is avoided.

While in describing the invention, I have referred in detail to the form, arrangement and construction of the various parts thereof, the same is to be considered only in the illustrative sense so that I do not wish to be limited thereto except as may be specifically set forth in the appended claims.

I claim as my invention:

1. In a locomotive boiler firebox, a water steaming and circulating longitudinally positioned element therein including a fiat, hollow, elongated body having two ends, the top of said body presenting an elongated opening in the crown sheet of the firebox and a plurality of tubular inlet necks for said element, each connected at one end to the bottom of an associated end of the body, said necks extending in opposite directions longitudinally of the body and,

crossing each other, said necks communicating with the water space of the boiler at a point below the crown sheet.

2. In a locomotive boiler firebox, a water steaming and circulating element therein including a flat, hollow, elongated body arranged longitudinally of the firebox with its top presenting an elongated opening in the crown sheet, said body having front and rear ends, and a plurality of tubular inlet necks for said element and each connected at one end to the bottom of an associated end of the body and extending longitudinally thereof in opposite downward, crossing directions from said ends of the body and communicating with the water space of the boiler at a point below the crown sheet.

3. In a locomotive boiler firebox, a water steamin and circulating element therein including a fiat, hollow, elongated body arranged longitudinally of the firebox with its top presenting an elongated opening in the crown sheet, said body having front and rear ends and a plurality of tubular inlet necks for said element and each connected at one end to the bottom of an associated end of the body and extending downwardly therefrom in opposite and crossing directions longitudinally of both the firebox and the body and communicating with the water space of the boiler at a point below said crown sheet, said inlet necks crossing each other.

4. In a locomotive boiler firebox, a hollow water steaming and circulating element therein including a body arranged longitudinally of the firebox with its top presenting an elongated opening in the crown sheet, said body having front and rear ends and a plurality of tubular inlet necks for said elements, one of said necks being connected at one end to the bottom of the front end of the body and extending downwardly and rearwardly therefrom, the other of said necks being connected at one end to the bottom of the rear end of the body and extending downwardly and forwardly therefrom, the other end of the first mentioned neck opening through one of the sheets of the firebox toward the rear end thereof at a point below the crown sheet and the other end of the second mentioned neck opening through one of the sheets of the firebox toward the front end thereof at a point below the crown sheet.

5. In a locomotive firebox, a hollow Water steaming and circulating element therein including a body formed to provide front, rear and in termediate compartments that open through the crown sheet of the firebox by means of a common outlet, the bottoms of the front and rear compartments being disposed at elevations lower than that of the intermediate compartments,

and a plurality of tubular inlet necks for said element, one of said inlet necks being connected at one end to the bottom of the front compartment and extending downwardly and rearwardly therefrom to open through one of the sheets of the firebox toward the rear end thereof at a point below the crown sheet, and the other of said necks being connected at one end to the bottom of the rear compartment and extending downwardly and forwardly therefrom to open through one of the sheets of the firebox toward the front end thereof at a point below the crown sheet.

6. In a locomotive boiler firebox, a water steaming and circulating element longitudinally positioned therein including a fiat, hollow, elongated body formed to provide front and rear end and intermediate compartment portions which open through the crown sheet of the firebox by a common outlet mouth, the bottom of the front and rear compartment portions being disposed at elevations lower than that of the intermediate compartment, and a plurality of tubular inlet necks for and extending longitudinally of said body, one of said necks being disposed in the vertical plane of said mouth and being connected at one end to one of said end compartment portions and extending downwardly in an angular direction therefrom to open through one of the sheets of the firebox below the crown sheet and the other of said inlet necks being offset laterally from the plane of the first mentioned neck and being connected at one end to the other of said compartment portions and extending downwardly therefrom in an opposite angular direction to said first-mentioned neck to open through another one of the sheets of the firebox below the crown sheet thereof, said inlet necks crossing each other.

'7. In combination with the crown sheet of a locomotive boiler firebox, a thermic siphon ineluding a substantially perpendicularly and longitudinally disposed fiat hollow body having an upper part opening through the crown sheet and having a bifurcated lower part providing inlet openings for said body, one of which is offset laterally from the plane of the upper part of said body, and tubular means providing inlet necks for said body, each opening at one end through an associated sheet of the firebox below the crown sheet, said inlet necks extending longitudinally of the body, in opposite upward directions and crossing each other and being connected at the other end with the inlet openings for the body.

8. A thermic siphon for use in a locomotive boiler firebox and embodying therein, a flat hollow water steaming wall including an elongated body formed to provide front and rear end and intermediate compartments, all of said compartments having a common outlet at the top, the said end compartments having individual inlet portions extending longitudinally of the body and facing in opposite downward directions that cross each other.

'9. A thermic siphon for use in a locomotive boiler firebox and embodying therein, a fiat hollow water steaming wall including a body formed to provide front and rear end and intermediate compartments, all of said compartments having a common outlet at the top, and the said end compartments each having individual inlet portions extending longitudinally of the body and facing in opposite downward but crossing directions, with one of said end compartments being formed so that its inlet is offset laterally with respect to the inlet of the other end portion.

GUST J. CHRISTENSON. 

